Just to start with I'll start say right now that I work in this field, and I'll refrain from making some sort of sales pitch too!
Microsoft's offering on first acquaintance looks like a half decent service. However, it doesn't work very well across different email platforms; I've seen some woeful results after a lot of hard work has been put in by the user, and I could mention several other email marketing solutions that face the same obstacle.
As for alternative solutions, well there are a lot out there and I always suggest taking a look round is a good idea. But don't be taken in by super cheap headline prices or promises that email marketing will transform your business. Like anything else, the bargain bucket end of a market can be a risky lake to swim. Instead, think about how email marketing can become a key component in how you promote and communicate with your customers and prospects as well as supporting your other business development and marketing efforts, such as telemarketing, events, web, and so on.
Sean commented that email marketing is cheap and has a throwaway element. With all due respect to the poster that's simply not correct. If you take a casual approach to email marketing then you're risking your business reputation. Invest some time, thought and commitment and it can make a tangible difference, not just to your opportunities pipeline but to many other facets of your business as well.